Catheter for modified perfusion

ABSTRACT

A catheter adapted for use in passing fluids and medicines therethrough for use in the perfusion or reperfusion of blood or blood-fluid mixtures into the arteries, veins, tissues, conduits, or organs of a patient is disclosed. The catheter has an elongate tubular body with an elongate central lumen defined therein. The catheter also includes at least one occlusive balloon disposed on the exterior of and about the tubular body, and a drug delivery lumen defined within the tubular body separately of the central lumen and extending in the lengthwise direction of the tubular body. A drug delivery outlet is defined at and in communication with a distal end of the drug delivery lumen for permitting the delivery of fluids passed through the drug delivery lumen separate of any fluids passed through the central lumen of the catheter. A separate drug infusion port, in fluid communication with the drug delivery lumen, is provided at a proximal end of the catheter so that any desired fluids and/or medicines may be passed into the patient through the drug delivery lumen separately of the central lumen. The catheter may also include a pressure sensor at the distal end of the tubular body for measuring the pressure of fluid thereat during catheterization and/or fluid delivery therethrough.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to provisional U.S. PatentApplication Ser. No. 60/351,203, filed on Oct. 25, 2001, in the UnitedStates Patent and Trademark Office, which application is incorporatedfully herein by this reference.

FIELD OF THE INVENTION

[0002] The present invention relates in general to medical devices. Moreparticularly, the invention relates to a catheter adapted to passfluids, or blood in combination with fluids, therethrough for theperfusion or reperfusion of the veins, arteries, tissues, and organs ofa patient.

BACKGROUND OF THE INVENTION

[0003] The construction and use of catheters and related medical devicesis well known. Current technologies allow for the catheterization ofarteries and veins, and allow also for the expansion of atheroscleroticplaques in an angioplasty procedure. However, these existingtechnologies do not allow for the delivery of drugs, especiallyshort-acting drugs to the target area of an organ, for example theheart. In addition, the current devices which permit the delivery ofdrugs do not allow for the exact control of the concentration of thedrug at the site of action, because the drugs are delivered systemicallyand because the drug delivery may tend to vary due to the flow rate andthe volume of the drug(s) being passed through the catheter. Moreover,the controlled delivery of blood, fluids or a combination thereof cannotbe achieved, so the control over the conditions and compositions duringperfusion or reperfusion of organs and tissues cannot be exercised.

[0004] The current embodiments of catheters, as described above, allowthe application of principals of modified perfusion to organs andtissues. These principals have been developed and in use over the past10-15 years. However, the lack of a delivery technology, or in thisinstance, a delivery device, has impeded the clinical application ofmodified perfusion and reperfusion.

[0005] What is needed, therefore, is an improved catheter constructed topermit the controlled delivery of blood, or a combination of fluids,medications and blood therethrough and into the arteries, veins, organs,or tissues of a patient, and which is also suitable for use in themodified perfusion or reperfusion of the arteries, veins, organs, ortissues of a patient.

SUMMARY OF THE INVENTION

[0006] The present invention overcomes some of the design deficienciesof the known catheters by providing a catheter adapted for thecontrolled delivery of fluids and/or medicines therethrough and into thearteries, veins, organs, or tissues of a patient, specifically allowingdelivery at known fluid pressures in the distal artery, vein or otherconduit or tissue. The catheter of this invention includes an elongatetubular body defining a continuous central lumen extending through thecatheter body from a proximal end to a spaced distal end thereof. Afluid-tight connector, which may for example comprise a luer-typeconnector, is provided at the proximal end of the tubular body and is insealed fluid communication with the central lumen.

[0007] In use, a sheath is inserted into the access site (artery, veinor other conduit) through which the catheter is thereafter inserted.This sheath is retained in the vessel during the catheter procedure, andis provided with a port defined therein and through which the pressurein proximity to the sheath, that is the proximal pressure, may bemeasured. The proximal pressure measurement port may be placed intosealed fluid communication with any of the known types of fluid pressuremeasurement devices, as desired.

[0008] In one embodiment, an occlusive balloon is positioned to andaffixed about the tubular body of the catheter, for example at thedistal end thereof, and is adapted for use in known fashion. A ballooninflation port is defined within the tubular body of the catheter, andopens into the interior of the balloon. The inflation port is formed tobe in sealed fluid communication with an elongate balloon inflationpassageway defined within or external to the catheter body. Theinflation passageway terminates at its opposite end in a balloon inletport at the proximal end of the catheter body. The catheter may be usedin conjunction with either one of a pressure wire or a flow wire, inconventional and otherwise known fashion.

[0009] In a second embodiment, a pair of spaced occlusive balloons arepositioned on and about the catheter, and are adapted to be inflated ordeflated together, or separately, all as desired. Separate ballooninflation ports are defined within the tubular body of the catheter, andeach port opens into the interior of its respective balloon. Therespective inflation ports are each formed to be in sealed fluidcommunication with separate and elongate balloon inflation passagewaysdefined within, or external to, the catheter body. The inflationpassageways each terminate at their opposite ends in a respectiveballoon inlet port at the proximal end of the catheter body.

[0010] In one embodiment, a solid state or electronic pressure sensor isaffixed to the exterior of, or is otherwise embedded within, the distalend of the catheter and is adapted for measuring fluid pressure duringcatheterization, as well as the pressure of fluid delivery therethrough.In an alternate embodiment, a fluid filled pressure port is defined atthe distal end of the catheter body and extends through a fluid filledpassageway to the proximal end of the catheter body, where any knowntype of a fluid pressure measurement device, for example a fluid-filledtransducer, adapted for use with a fluid pressure port may be used.

[0011] In yet another embodiment of the invention, the catheter isprovided with an elongate drug delivery lumen defined within or externalto the catheter body and separately of the central lumen. The drugdelivery lumen defines a drug delivery outlet or discharge port at thedistal end of the catheter in sealed fluid communication with the drugdelivery lumen. The drug delivery lumen terminates at its proximal endin a drug infusion port which is also in sealed fluid communication withthe drug delivery lumen. So constructed, the desired fluids may be mixedexternally of and/or otherwise passed separately of the fluids withinthe central lumen in a controlled manner of delivery.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is cross-sectioned view of a first embodiment of thecatheter of the invention.

[0013]FIG. 2 is a cross-sectioned view of the distal end of the catheterof FIG. 1.

[0014]FIG. 3 is a perspective view of the distal end of the catheter ofFIG. 1.

[0015]FIG. 4 is cross-sectioned view of a second embodiment of thecatheter of the invention having a drug delivery lumen formed therein.

[0016]FIG. 5 is a partial and enlarged view of the proximal end of thecatheters of FIGS. 1 and 4.

[0017]FIG. 6 is a cross-sectioned view of the distal end of the catheterof FIG. 4.

[0018]FIG. 7 is a perspective view of the distal end of the catheter ofFIG. 4.

[0019]FIG. 8 is a cross sectioned view of a two occlusive balloonembodiment of the catheter of the invention.

DETAILED DESCRIPTION

[0020] Referring now in detail to the drawings, in which like referencecharacters indicate like parts throughout the several views, a firstembodiment of a catheter 5 of the invention is illustrated in FIGS. 1-4.The catheter is formed as an elongate tubular body 7 which defines acontinuous central lumen 8 therein. The central lumen extends from aproximal end 10 of the catheter body to a spaced distal end 11 thereof.The central lumen 8 is preferably designed to allow for a fluid flowtherethrough, either blood or a crystalloid, or a combination thereof,of approximately 100 milliliters per minute, this flow ranging fromapproximately one to approximately one-hundred milliliters per minute.Also, this embodiment of the catheter, as well as the other catheterembodiments discussed herein, may be used in conjunction with either oneof a pressure wire or a flow wire, in conventional and otherwise knownfashion.

[0021] A luer-type of connector 13 (FIG. 5) is provided at the proximalend of the catheter, and which is constructed in known fashion forreceiving in sealed fluid-tight communication the supply line(s) for thefluid(s) to be passed through the central lumen. The proximal end of thecatheter is also provided with a proximal insertion sheath 14 extendedabout the exterior surface of the catheter, with a septum 15 (FIG. 5)sealing the sheath about the catheter.

[0022] The proximal insertion sheath allows the catheter to be insertedinto the vessel for ultimate vascular access of the target vessel ororgan. It is modified to allow measurement of vascular pressure in thevicinity of the insertion of the sheath. The sheath is similar to thosecurrently used to insert catheters by the Seldinger technique, in whicha guide wire is inserted into the access vessel from a percutaneousapproach or direct cut-down, and over which a guide catheter and astylet are inserted into an artery or vein convenient for use as anaccess. The stylet (not shown) is subsequently removed as the guidewireand guide catheter are advanced.

[0023] The septum 15 at the proximal end of the sheath closes to preventthe flow of blood from inside the vessel to the outside. The guidewire,followed by the perfusion catheter, is then inserted through the septumwhich seals around the wire and catheter to maintain hemostasis. Theguidewire and catheter are then advanced toward the target vessel inknown fashion, for example, as used in angioplasty or angiographicprocedures. The perfusion catheter may be used in conjunction with aguide catheter for procedures performed in known fashion for angioplastyand/or other coronary catheterization procedures. In addition, theperfusion catheter may be used in conjunction with, or in lieu of anangioplasty catheter to cross the plaque site and expand the site ofstenosis using the catheter balloons.

[0024] The sheath 14 includes an outlet or a pressure measurement port16 defined therein for use in measuring the vessel blood pressure nearthe proximal end of the catheter in association with any of the knowntypes of fluid pressure measurement devices (not illustrated) adapted tobe received thereat. The port 16 may be fashioned as a luer-type ofconnector, if so desired. The pressure sheath 14 in association with theoutlet port 16 may thus be used to measure and/or monitor the proximalarterial or venous blood pressure of the patient, or used as a targetpressure for use in adjusting the fluid pump rates to in turn controlthe distal, arterial or venous fluid flow rate and pressures. Inaddition, the port 16 may be used as a general intravenous access foradministration of fluids or drugs.

[0025] An occlusive balloon 18 of known construction is carried on andextends about the tubular body of the catheter intermediate the proximaland the distal ends, respectively, of the catheter as illustrated inFIGS. 1, 2, 4, and 6. A balloon inflation port 19 is defined within thebody of the catheter in sealed fluid/air-tight communication with theballoon interior. An elongate balloon inflation passageway 21 is definedwithin or otherwise formed as a part of the catheter body separate ofthe central lumen. The passageway 21 is a hydraulic passageway in fluidcommunication with the balloon inflation port, and extends to a ballooninlet port 22 situated at the proximal end of the catheter (FIG. 1), towhich a known type of balloon inflation device (not illustrated) may beattached.

[0026] As shown in FIGS. 1 and 4, a solid state pressure sensor 24 maybe affixed to the exterior of, or otherwise formed, positioned, orembedded within the distal end of the catheter body, and is adapted foruse in measuring the target or ambient fluid pressure(s) at the distalor treatment end of the catheter during catheterization, as well asduring the infusion of any fluids through the distal end of the catheterand into the arteries, veins, organs, or tissues of the patient. Thedistal pressure sensor may thus comprise any one of the known types ofsolid-state transducers for sensing and transmitting high fidelitypressure signals such as those manufactured by Millar Instruments, Inc.of Houston, Tex., as well as any other type of solid state transducerwhich is adapted for use in pressure or tactile sensation measurement.The lead wires of the sensor 24 are passed to a suitable plug (notillustrated) positioned at the proximal end of the catheter, and maytherefore be passed through a communications channel 49 (FIG. 8) definedwithin the body of the catheter, or through an existing passageway, forexample the passageway 31 (FIGS. 2 and 6) of the fluid-filled pressuresensor available for use with the catheter of this invention.

[0027] Referring now to FIGS. 2 and 6, an alternate embodiment of thecatheter is disclosed having an alternate means for measuring thepressure at the distal end of the catheter. As shown in these twofigures, the distal end of the catheter is provided with a fluid-filleddistal pressure port 30 defined therein and extending in sealed fluid(hydraulic) communication through a passageway 31, defined within thecatheter, to a suitable discharge port (not illustrated), for example aluer type of port, to which a suitable fluid pressure measurementdevice, for example one of the known types of fluid-filled transducers,is connected. The use of fluid filled passageways, and of fluid-filledpressure ports for measuring fluid pressures is well known and withinthe scope of those skilled in the art, and thus is not described ingreater detail herein.

[0028] Referring now to FIGS. 4 and 6, yet another embodiment of thecatheter of this invention is disclosed. In this embodiment of thecatheter a distal drug outlet or delivery port 27 is defined within anelongate drug delivery lumen 25 defined within and extending in thelengthwise direction of the catheter body. The drug delivery lumen 25 isdefined within the catheter body separately of the central lumen 8thereof such that the fluids passed therethrough will not mix with thosewithin the central lumen, but will instead be mixed at the distal tip ofthe catheter. The drug delivery port is formed to be in sealedfluid-tight communication with the drug delivery lumen. The drugdelivery lumen also has a drug infusion port 28 defined therein, asillustrated in FIG. 4, for the passage of drugs or drug-fluid admixturestherethrough and into the drug delivery lumen.

[0029] So provided, the drug delivery lumen allows for the delivery offast-acting, and/or rapidly degrading drugs through the distal end ofthe catheter, and into the treatment area within the surroundingarteries, veins, organs, or tissues of the patient. Examples offast-acting and/or rapidly degrading drugs of the type that may be usedwith the invention include, but are not limited to, adenosine and nitricoxide. The distal infusion of these drugs through the drug lumen willprevent these short-acting agents from being metabolized or otherwisedegraded by blood or other fluids during transit in the catheter lumen,and/or will prevent the interaction of the drugs before they enter thepatient's blood stream, organs, or tissues.

[0030] In use, the catheter is introduced into the appropriate arterialor venous vasculature and guided to the target area through a pre-placedsheath-and guidewire, and guided to the target location in knownfashion. In a first method of use therefore, the catheter may befluoroscopically guided into a coronary artery that is partially orentirely blocked. The catheter is positioned at the point of occlusion,and the occlusive balloon is inflated as it is used in an angioplastyprocedure, for example. In one embodiment of the procedure, the ballooncan then be deflated and a cardioprotective agent may be infused at thephysician's discretion to attenuate reperfusion injury or arrhythmias,or to introduce a local anti-arrhythmic or local inotropic agent.

[0031] In an alternate method of use, the catheter can be placed acrossthe blockage and then inflated as per the use of an angioplastycatheter, and left deployed to introduce blood, fluids, or blood-fluidmixtures therethrough while preventing the admixture of native blood andblood flow therewith. The blood or blood-fluid mixture may containcardioprotective drugs or anti-arrhythmic drugs to once again attenuatereperfusion injury, and so on. If so desired, blood or blood-fluidmixtures (i.e., hemodiluted blood) can be introduced through thecatheter to prevent ischemia during the period of occlusive ballooninflation. As known, the benefit of including blood in a blood-fluidmixture is that oxygen is provided to the tissue, nutrients andendogenous substrates are included, as are endogenous anti-oxidants.Also, the flow rate and the pressure of the fluid can be controlled tostay within physiological and target therapeutic limits.

[0032] The complete occlusion of the blood vessel allows the physicianto control the composition of the perfusion fluid, its flow rate, andpressure to the distal tissue or organ. In another embodiment of theprocedure, the balloon may be partially deflated, or deflated accordingto a specified time algorithrim proceeding from full inflation to fulldeflation to allow for controlled blood flows. In addition, the timeduration of inflation can be controlled by appropriate and known typesof balloon inflation-deflation devices connected to the proximal end ofthe catheter at the luer lock (or other configuration) port.

[0033] By providing the drug delivery lumen 25, in association with thedrug delivery port 27, rapidly deactivated drugs may be passedtherethrough which allows for the admixture of drugs at the tip, i.e.,the distal end, of the catheter rather than in the proximal portionthereof, or in the delivery device (not illustrated) affixed to thefluid-tight connector at the proximal end of the catheter. The desireddrug or drugs will be infused through the drug infusion port 28 at theproximal end of the catheter, and outside of the patient's body.

[0034] Referring now to FIG. 8, a double balloon, or two balloon,embodiment of the catheter is illustrated. In this configuration asecond occlusive balloon is spaced from the first occlusive balloon by adistance in the range of from approximately 0.5 to approximately 10centimeters. This construction allows for the accumulation of fluidswithin this “inter-balloon” space. So constructed, this embodiment ofthe catheter allows for the measured delivery of medications into atarget vessel wall by exposing the wall directly to the medications suchthat the inter-balloon space is used for accumulating the fluids and/ormedications passed therein and that will, for example, bathe thevascular wall, the endothelium, or the plaque-containing area of thevessel wall.

[0035] The fluids/medications passed into the balloon inter-space can beretained in this space for a specified time, therefore allowing higherconcentrations of the desired medications to be used than wouldotherwise be tolerated if given systemically. Thereafter, themedications/fluids can be re-aspirated into the catheter so that theyare not delivered to the body, or can simply be washed into the generalcirculation when the balloons are deflated. The procedure forelimination of the medications used in the space between the balloonsdepends on toxicity and side effects of the medications. Applicationsusing this construction of the balloon catheter include, but are notlimited to, treatment for restenosis, localized endothelial injury, thestabilization of a plaque/plaque rupture, local coagulation,stabilization of the vascular endothelium by preventing inflammatoryactivation, attenuating cell proliferation by contact withanti-proliferative agents, delivery of gene therapy directly to thevessel wall, or other localized changes in the vessel wall or itsconstituents. In another application of this double balloon device, thespace between the two balloons (the balloon inter-space) can be placedat the branch-point of a vessel, so that the fluid or drugs infused intothis space, confined by the two balloons, will be selectivelydistributed into that branch.

[0036] Referring to FIG. 8, therefore, the catheter 5 is once againshown as having the elongate tubular body 7 with the continuous centrallumen 8 defined therein extending from the proximal end 10 of thecatheter body to the distal end 11 thereof. The catheter of FIG. 8 has afirst occlusive balloon 34 positioned on the catheter body intermediatethe proximal and distal ends thereof. An inflation port 35 is definedwithin the catheter body in fluid communication with a passageway 36defined within the catheter body, and which extends to the proximal endthereof. A second occlusive balloon 38 is also positioned on thecatheter body, intermediate the first balloon 34 and the distal end ofthe catheter. A second balloon inflation port 39 is defined within thetubular body of the catheter in fluid communication with a passageway 40defined within the catheter body and extending to the proximal endthereof.

[0037] Each of the passageways 36, 40 are formed separately of oneanother, and each is also constructed to be placed into sealed fluidcommunication with a balloon inlet port or lumen 42 constructed toinflate the balloons 34,38, respectively, separately or together, asdesired. An inflation syringe or bulb (not illustrated) will be attachedto the inflation lumen 42 for inflating the occlusive balloons, and isconstructed to allow for the inflation and/or deflation of the balloonsseparately or together, as desired, the syringe being of knownconstruction and used in known fashion.

[0038] A drug delivery port 44 is defined within the catheter body suchthat it is positioned between the occlusive balloons 34 and 38, in whathas been referred to as the balloon inter-space. The drug delivery portis in sealed fluid communication with a passageway 45 defined within thecatheter body, which passageway extends in sealed fluid communication toa drug infusion port 46 at the proximal end of the catheter. The desiredfluids, for example blood or blood-fluid mixtures, or drug admixtures,are therefore mixed externally of the catheter and are then passed intothe drug infusion port, through the passageway 45, and exit the catheterbody from the drug delivery port once at least one, or both, of theocclusive balloons have been inflated, as described in greater detailbelow.

[0039] Still referring to FIG. 8, the catheter is shown with a distalpressure sensor 48, which pressure sensor may be a solid-state sensor ora fluid-filled pressure port of the types described in greater detailabove. The fluid-filled or solid-state pressure sensors are optionalembodiments of the catheter. A conduit/passageway 49 is defined withinthe catheter body and extends from the pressure sensor to the proximalend of the catheter for connection to a suitable pressure measurementdevice of known construction for the type of pressure sensor being used.If, for example, a solid-state pressure sensor is used, the lead wires(not illustrated) which would extend from the sensor will be passedthrough the conduit 49 to the proximal end of the catheter body.Alternately, and if so desired, the lead wires from the solid-statepressure sensor may instead be embedded within the wall of the catheterbody rather than passed through the conduit/passageway 49. If thepressure sensor is a fluid-filled port, however, then the passageway 49will also be fluid-filled and will extend to a suitable fluid pressuremeasurement device (not illustrated), as known.

[0040] The method of using the two-balloon catheter of FIG. 8 includesthe steps of inserting the catheter into the desired artery, vein,vessel or conduit within the body for treating a segment of the conduitby isolating the target segment through the inflation of the twoocclusive balloons. Once the balloons are inflated, the desired blood,fluids, and/or medications are injected into the catheter and passedthrough the drug delivery port into the inter-space between the balloonsto “dwell” in this area. As the volume of this area is known, acorresponding and pre-determined volume of the desired fluids/drugs canbe injected into the inter-balloon area to prevent the spillover andpossible distribution of the fluids/drugs into the patient or systembeyond this defined area. Thereafter, the medications may be evacuatedfrom the inter-space back through the drug delivery port in order toavoid any toxicity, or the medications may be allowed to wash out intothe system by deflating the balloons if appropriate. This constructionis useful where the catheter diameter may not support the flow of bloodtherethrough, i.e., the catheter is a low-profile configuration, and mayalso allow for the delivery of blood, fluids, and/or combinationstherethrough to metabolically support the distal tissue and preventischemia therein, or provide for the delivery of tissue-protectivemedications.

[0041] It is anticipated that either or both of the pressure sensorarrangements described herein may be used with any one of the severalembodiments of the catheter of the invention described herein, asdesired. It is also anticipated that the catheter of the invention maybe used with or without a drug delivery lumen formed as a part thereof,if so desired. Accordingly, it is anticipated that the catheter of thisinvention may be used with any desired one or combination of a distalpressure sensor and/or a drug delivery lumen as disclosed hereinabove,as well as with one or two occlusive balloons, as described in greaterdetail below. Therefore, the catheter of the invention may include anyone or combination of the several features disclosed hereinabove in asingle catheter, as desired.

[0042] The catheter 5, in all of its embodiments as illustrated in FIGS.1-8 hereof, is constructed of known materials, which materials areparticularly suited for, and approved for use in surgical orintravascular procedures. The central lumen 8 of the catheter is sizedsufficiently for the delivery of fluids, blood, or blood-fluid mixturestherethrough. The occlusive balloons 18, 34, and 38, respectively, areeach sized and shaped so that they may be inflated through theirrespective balloon inflation ports 19, 35, and 39 such that therespective balloons seal the artery or vein within which they arereceived, and to also allow for the infusion of the desired blood, orblood-fluid mixtures in a controlled manner through the catheter andinto the veins, arteries, conduits, or tissues without the admixture ofblood in the proximal portion of the catheter. The respective balloonscan also be partially inflated to allow for a mixture of the blood fromthe patient's vessel with any crystalloid or drugs passed through thecentral lumen and/or the drug delivery lumen.

[0043] Each of the distal pressure sensors 24 and 49, as well as thedistal pressure port 30, can be used to measure the distal fluidpressures in the vessel or organ during catheterization or infusion ofthe blood, fluid, or blood-fluid mixtures into the patient, and can alsobe used to control the flow rate of fluid therethrough if, for example,a separate infusion pump or device (not illustrated) is being used. Inthe alternative, the distal pressure sensor may be used to measure thedistal fluid pressures for the determination and the calculation of thecoronary or other vascular reserves thereat, or other vascular indicesin which pressure is used as a coefficient.

[0044] Although several embodiments of the invention have been disclosedin the foregoing specification, it is understood by those skilled in theart that many modifications and other embodiments in the invention willcome to mind to which the invention pertains, having the benefit of theteaching presented in the foregoing description and the associateddrawings. It is thus understood that the invention is not limited to thespecific embodiments disclosed hereinabove, and that many modificationsand other embodiments are intended to be included within the scope ofthe invention. Moreover, although specific terms are employed herein,they are used only in a generic and descriptive sense, and not for thepurposes of limiting the described invention, and the words “a,” “and,”or “the” as they appear hereinabove may mean one or more, depending uponthe context in which the words are used.

I claim:
 1. A catheter adapted for use in passing fluids therethroughand into the arteries, veins, tissues, conduits, or organs of a patient,said catheter comprising: an elongate tubular body having a proximal endand a spaced distal end; a central lumen defined within said body andextending from the proximal end to the distal end thereof; meansapproximate the proximal end of said body for sensing the fluid pressuretherein; means positioned at the distal end of said body for sensing thefluid pressure thereat; an occlusive balloon disposed on the exterior ofsaid body; and means for inflating said balloon.
 2. The catheter ofclaim 1, further comprising a drug delivery lumen defined within saidbody separately of said central lumen and extending in the lengthwisedirection of said body, a drug delivery outlet at the distal end of thebody in fluid communication with the drug delivery lumen, and a druginfusion port in fluid communication with the drug delivery lumen. 3.The catheter of claim 1, said means for sensing the fluid pressureapproximate the proximal end of the catheter body comprising a sheathextended about the exterior periphery of the catheter body, said sheathdefining an outlet port therein.
 4. The catheter of claim 3, furthercomprising a pressure measurement device in sealed fluid communicationwith said outlet port.
 5. The catheter of claim 3, wherein the pressureoutlet port further comprises a luer-type of connector.
 6. The catheterof claim 3, further comprising a fluid-filled transducer in sealed fluidcommunication with the pressure outlet port
 7. The catheter of claim 1,said means for sensing the fluid pressure at the distal end of thecatheter comprising a solid-state pressure measurement device.
 8. Thecatheter of claim 7, wherein said solid-state pressure measurementdevice is embedded within the tubular body of the catheter.
 9. Thecatheter of claim 7, said solid-state pressure measurement devicecomprising a transducer.
 10. The catheter of claim 1, said means forsensing the fluid pressure at the distal end of the catheter comprisinga fluid-filled pressure port.
 11. The catheter of claim 1, said meansfor inflating the occlusive balloon comprising an elongate ballooninflation passageway defined within the tubular body, a ballooninflation port defined with the tubular body in fluid communication withsaid passageway and the interior of said balloon, and a balloon inletport in fluid communication with said passageway.
 12. The catheter ofclaim 1, further comprising a luer-type of connector disposed at theproximal end thereof and in sealed fluid communication with the centrallumen.
 13. The catheter of claim 1, further comprising a secondocclusive balloon spaced from the occlusive balloon.
 14. The catheter ofclaim 13, said second balloon being spaced from the occlusive balloon bya distance in the range of from approximately 0.5 to approximately 10centimeters.
 15. A catheter adapted for use in passing fluidstherethrough and into the arteries, veins, tissues, conduits or organsof a patient, said catheter comprising: an elongate tubular body havinga proximal end and a spaced distal end; a central lumen defined withinsaid body and extending from the proximal end to the distal end thereof;an occlusive balloon disposed on the exterior of the body; a drugdelivery lumen defined within said body separately of the central lumenand extending in the lengthwise direction thereof; a drug deliveryoutlet in fluid communication with the drug delivery lumen at the distalend of the body; and a drug infusion port in fluid communication withthe drug delivery lumen.
 16. The catheter of claim 15, furthercomprising means for inflating said balloon.
 17. The catheter of claim16, the means for inflating said balloon comprising: an elongate ballooninflation passageway defined within the tubular body; a ballooninflation port defined with the tubular body in fluid communication withsaid passageway and the interior of said balloon; and a balloon inletport in fluid communication with said passageway.
 18. A method of usinga catheter to pass fluids and medicines therethrough and into anoccluded artery or vein, said method comprising: introducing an elongatetubular body having a proximal end and a spaced distal end into thedesired arterial or venous vasculature; positioning the distal end ofthe catheter at the point of the occlusion; inflating an occlusiveballoon disposed on the exterior of the body; and passing the fluidthrough a central lumen defined within the tubular body of the catheterand extending from the proximal end to the distal end thereof.
 19. Themethod of claim 18, further comprising deflating the occlusive balloonprior to passing the fluid through the central lumen.
 20. The method ofclaim 18, further comprising passing the fluids and medicines through adrug delivery lumen defined with the tubular body separately of thecentral lumen, and delivering the fluids and medicines into the arterialor venous vasculature through a drug delivery outlet defined at thedistal end of the body and in fluid communication with the drug deliverylumen.
 21. The method of claim 20, further comprising passing the fluidsand medicines into a drug infusion port in fluid communication with thedrug delivery lumen.
 22. The method of claim 20, further comprisingmixing the fluids and medicines and any desired fluids togetherexternally of the catheter and then passing the fluids and medicinesinto a drug infusion port in fluid communication with the drug deliverylumen.
 23. A method of using a catheter to pass fluids and medicinestherethrough and into an occluded or narrowed artery or vein, saidmethod comprising: introducing an elongate tubular body having aproximal end and a spaced distal end into the desired arterial or venousvasculature; positioning the distal end of the catheter across the pointof the occlusion or narrowing; inflating an occlusive balloon disposedon the exterior of the body; and passing the fluids and medicinesthrough a central lumen defined within the tubular body of the catheterand extending from the proximal end to the distal end thereof.
 24. Themethod of claim 23, further comprising passing the fluids and medicinesthrough a drug delivery lumen defined with the tubular body separatelyof the central lumen, and delivering the fluids and medicines into thearterial or venous vasculature through a drug delivery outlet defined atthe distal end of the body and in fluid communication with the drugdelivery lumen.
 25. A method of using a catheter to pass fluids andmedicines therethrough and into the organs and tissues of a patient,said method comprising: introducing an elongate tubular body having aproximal end and a spaced distal end into the arteries, veins, conduits,organs and tissues of a patient; positioning the distal end of thecatheter at a desired location within the arteries, veins, conduits,organs and tissues of the patient; inflating an occlusive balloondisposed on the exterior of the body; and passing the fluids andmedicines through a central lumen defined within the tubular body of thecatheter and extending from the proximal end to the distal end thereofand into the arteries, veins, conduits, organs and tissues of thepatient.
 26. The method of claim 25, further comprising passing thefluids and medicines through a drug delivery lumen defined with thetubular body separately of the central lumen, and delivering the fluidsand medicines into the arteries, veins, conduits, organs and tissues ofthe patient through a drug delivery outlet defined at the distal end ofthe tubular body and in fluid communication with the drug deliverylumen.
 27. A catheter adapted for use in passing fluids and medicinestherethrough and into the arteries, veins, tissues, conduits or organsof a patient, said catheter comprising: an elongate tubular body havinga proximal end and a spaced distal end; a central lumen defined withinsaid body and extending from the proximal end to the distal end thereof;means approximate the proximal end of said body for sensing the fluidpressure therein; means positioned at the distal end of said body forsensing the fluid pressure thereat; a first occlusive balloon disposedon the exterior of said body intermediate the proximal and the distalends thereof; means for inflating said first balloon; a second occlusiveballoon disposed on the exterior of said body intermediate the firstocclusive balloon and the distal end of the catheter body; means forinflating said second balloon; a drug delivery port defined within thecatheter body intermediate the first occlusive balloon and the secondocclusive balloon; and means for passing the fluids and medicinesthrough said drug delivery port and into the space between said firstand said second occlusive balloons, respectively.
 28. The catheter ofclaim 27, further comprising means for separately inflating anddeflating the first occlusive balloon and the second occlusive balloon,respectively.
 29. A method of using a catheter to pass fluids andmedicines therethrough and into an artery, vein, organ or the tissues ofa patient, said method comprising: introducing an elongate tubular bodyhaving a proximal end and a spaced distal end into the desired artery,vein, conduit, organ or tissue, the tubular body defining a continuouscentral lumen therein extending from the proximal end to the distal endof the body; positioning the distal end of the catheter approximate atreatment point within the desired artery, vein, conduit, organ ortissue; inflating a first occlusive balloon disposed on the exterior ofthe catheter body intermediate the proximal end and the distal endthereof; inflating a second occlusive balloon disposed on the exteriorof the body and spaced from said first balloon; and passing the fluidsand medicines through the catheter body and into the space defined byand between the first occlusive balloon and the second occlusive balloonrespectively.
 30. The method of claim 29, further comprising treating atarget segment of the conduit by isolating the target segment with thetwo occlusive balloons.
 31. The method of claim 29, further comprisinginjecting the fluids and the medicines into the space between the twoocclusive balloons.
 32. The method of claim 29, further comprisingpermitting the fluids and medicines to dwell in the space between thetwo occlusive balloons.
 33. The method of claim 29, further comprisingevacuating the fluids and the medicines from the space between the twoocclusive balloons back through the catheter.
 34. The method of claim29, further comprising allowing the fluids and the medicines to wash outinto the system by deflating the two occlusive balloons.